The effects of dietary protein content and feeding level on the utilization of metabolizable energy (ME) and on the rates of gain, protein and fat deposition have been studied in seventy-two Iberian pigs growing from 15 to 50 kg body weight (BW) by means of comparative slaughter experiments. The animals were fed on six diets providing 223, 192, 175, 156, 129 and 101 g crude ideal protein (N £ 6·25; CP)/kg DM and 14·64, 14·14, 14·37, 14·80, 15·36 and 15·53 MJ ME/kg DM respectively. Each diet was offered at three levels of feeding: 0·60, 0·80 and 0·95 £ ad libitum intake. Protein deposition (PD) increased significantly (P,0·01) with each decrease in dietary CP content and reached a maximum value (74·0 g) when the diet providing 129 g CP/kg DM (6·86 g digestible ideal protein/MJ ME) was offered at the highest feeding level. This feeding regimen resulted in average values for live-weight gain and retained energy (RE) of 559 g/d and 10·9 MJ/d respectively. RE increased significantly (P, 0·001) from 480 to 626 kJ/kg BW 0·75 with each decrease in dietary CP content from 192 to 129 g/ kg DM. Raising the level of feed intake led to significant linear increases in PD and RE irrespective of the diet fed (P,0·001). When diets approaching an adequate supply of CP were given, the net efficiency of use of ME for growth (k w ) and the maintenance energy requirements were 58·2 % and 422 kJ/kg BW 0·75 per d respectively.

The effects of dietary protein content and feeding level on the utilization of metabolizable energy (ME) and on the rates of gain, protein and fat deposition have been studied in seventy-two Iberian pigs growing from 15 to 50 kg body weight (BW) by means of comparative slaughter experiments. The animals were fed on six diets providing 223, 192, 175, 156, 129 and 101 g crude ideal protein (N £ 6·25; CP)/kg DM and 14·64, 14·14, 14·37, 14·80, 15·36 and 15·53 MJ ME/kg DM respectively. Each diet was offered at three levels of feeding: 0·60, 0·80 and 0·95 £ ad libitum intake. Protein deposition (PD) increased significantly (P,0·01) with each decrease in dietary CP content and reached a maximum value (74·0 g) when the diet providing 129 g CP/kg DM (6·86 g digestible ideal protein/MJ ME) was offered at the highest feeding level. This feeding regimen resulted in average values for live-weight gain and retained energy (RE) of 559 g/d and 10·9 MJ/d respectively. RE increased significantly (P, 0·001) from 480 to 626 kJ/kg BW 0·75 with each decrease in dietary CP content from 192 to 129 g/ kg DM. Raising the level of feed intake led to significant linear increases in PD and RE irrespective of the diet fed (P,0·001). When diets approaching an adequate supply of CP were given, the net efficiency of use of ME for growth (k w ) and the maintenance energy requirements were 58·2 % and 422 kJ/kg BW 0·75 per d respectively.

RESUMO O objetivo desse trabalho foi selecionar descritores de sementes em maracujazeiro obtidos por meio de análise digital de imagem utilizando os componentes principais. Para isto, foram analisados 95 descritores mensurados a partir da análise digital de imagens em sementes de 35 famílias de irmãos completos de maracujazeiro azedo. Foram avaliadas 50 sementes por família. Para avaliação dos descritores foi utilizado o método dos componentes principais e a seleção foi realizada com base em descartar a variável como maior coeficiente em cada componente com autovalor menor que 0,70, de acordo com as pressuposições de Jolliffe e Mardia. Foi possível reduzir o número de descritores, sendo selecionados cinco de cor, seis de geometria e seis de textura. A análise digital de imagem é uma ferramenta viável e eficiente na mensuração de descritores de sementes no maracujazeiro azedo. PALAVRAS-CHAVE: análise digital de imagem, componentes principais, Passiflora edulis L.